When your engine is switched off, the relay will isolate your leisure battery(s) from your main starter battery. So it does not drain your main starter battery and you will always be able to start your vehicle.
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12V 100 AMP HEAVY DUTY RELAY / SPLIT CHARGE RELAY DURITE 0-727-10
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Split Charge Relay VSR Voltage Sensitive PREMIUM 12V 60A For Campers, Motorhomes
Celsus Split Charge Relay 100a RL100 Car Audio Accessory Stereo Installation
